Air filter devices with gap sealing unit

ABSTRACT

An air filter device including an air filter unit and an expansion unit. The air filter unit includes a filter media assembly maintained by an outer frame assembly. The outer frame assembly defines exterior length, width and depth dimensions of the air filter device in an initial state. The expansion unit provides one or more of an expanded length, width or depth in an expanded state of the air filter device. Portions or an entirety of the expansion unit can provided apart from the air filter unit in a deliver condition of the air filter device, or can be assembled to the air filter unit prior to delivery to a user. The air filter devices of the present disclosure are useful with a wide variety of differently size air handling devices, able to readily seal with an air handling device compartment via the expansion unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/762,409, filed 13 Aug. 2018, which is a national stage filingunder 35 U.S.C. 371 of PCT/US2016/052047, filed 16 Sep. 2016, whichclaims the benefit of U.S. Provisional Application No. 62/222,836, filed24 Sep. 2015, the disclosures of which are incorporated by reference intheir entireties herein.

BACKGROUND

The present disclosure relates to air filters. More particularly, itrelates to expandable air filters, such as expandable HVAC air filters,appropriate for use with multiple, differently sized air filtercompartments.

Air filters are commonly used in forced air systems (e.g., residentialheating, ventilation and air conditioning (HVAC) systems) in order toremove dust, dirt particles and the like. With many HVAC installations,a disposable air filter is conventionally employed. Such air filterstypically include a filter media surrounded and supported by an outerframe. In addition to supporting the filter media, the outer framerigidly defines a perimeter size and shape of the air filter. Othersupporting and/or reinforcing components, such as mesh screens, adhesivebeads, etc., may also be included. After a period of use, these filtersbecome dirty or clogged and must be replaced.

To facilitate air filter replacement, HVAC systems conventionally housethe air filter within a user-accessible compartment. The air filter isplaced into and/or retrieved from the compartment via an access slot. Insome instances, the air filter alone is inserted through the slot. Inother instances, a separate cabinet is provided into which the airfilter is placed, followed by insertion of the loaded cabinet throughthe slot. In all instances, upon final insertion, a seal is desirablyestablished between the outer frame of the air filter and framework ofthe compartment so as to prevent airflow around the air filter duringuse (and thus prevent un-filtered airflow from passing through the HVACsystem). Preferred replacement air filters have a size that correspondswith the expected size (in terms of height, width and depth) of the HVACsystem's air filter compartment.

A number of “standard” HVAC air filter compartment sizes have gainedindustry acceptance over time and are widely employed. Replacement airfilter manufacturers, in turn, attempt to make available for retailpurchase air filters corresponding with these standard sizes, allowing acustomer to select a particular air filter that should fit their HVACsystem's compartment configuration. The rigid outer frame ofconventional air filters dictates that the replacement air filter hasthe same size when shipped to a retailer, when presented to potentialpurchases, and when installation to the HVAC system is attempted.Because these typical HVAC air filters are thus rather bulky, theyundesirably occupy a relatively large volume of space on transportationvehicles and retailer shelves. Further, where the retailer has limitedavailable shelf space and/or desires to display for purchase a largenumber of differently-sized air filters, only a small number oflarger-sized air filters (e.g., deep pleat air filters) can reasonablybe presented on the retailer's shelving system. When the small number ofa certain air filter size are subsequently removed from the shelf forpurchase and the retailer does not consistently replenish the displayshelf, it may undesirably appear to the next potential purchaser thatthe particular air filter size of interest is out of stock.

In addition, a potential customer may not immediately recall withconfidence the correct air filter size for their HVAC system while atthe retailer's place of business; this uncertainty can be exacerbatedwhen a large number of different air filter sizes are displayed. Ratherthan purchase a potentially incorrectly-sized air filter, the consumerwill instead decide to delay air filter replacement to a later date,potentially leading to inefficient operation of the HVAC system if a newair filter is not actually purchased for an extended period of time.

Moreover, the actual air filter compartment size associated with aparticular HVAC system will oftentimes deviate from the designated“standard” or expected size. For example, the HVAC system manufacturer'sspecifications may identify an air filter size of 16″×20″×4″, yet theactual air filter compartment is slightly smaller or slightly larger inone or more dimensions. Thus, a purchased 16″×20″×4″ replacement airfilter may not be an optimal fit for the actual HVAC system compartment(e.g., the purchased air filter may be too large for straightforwardinsertion, or may be too small and lead to suboptimal HVAC systemoperation). These circumstances can be frustrating for the user, and canlead to even greater uncertainty when considering the next replacementair filter purchase.

The above-described concerns with conventional replacement HVAC airfilters can also arise in other contexts. Many other types of airhandling devices or systems (e.g., room air purifiers, window airfilters, etc.) make use of a replaceable, rigid-frame air filter, and aplethora of differently-sized replacement air filters are presented forretail purchase. Once again, the relatively large number ofdifferently-sized air filters that must be displayed occupies valuableretail shelf space, and a potential purchaser will oftentimes be unsureas to which size is a best “fit” at the time of purchase.

SUMMARY

The inventors of the present disclosure recognize that a need exists foran air filter that overcomes one or more of the above-mentionedproblems.

Some aspects of the present disclosure relate to an air filter deviceincluding an air filter unit and an expansion unit. The air filter unitincludes a filter media assembly maintained by an outer frame assembly.The outer frame assembly defines exterior length, width and depthdimensions of the air filter device in an initial state. The expansionunit provides one or more of an expanded length, width or depth in anexpanded state of the air filter device. In some embodiments, portionsor an entirety of the expansion unit is provided apart from the airfilter unit in a deliver condition of the air filter device (e.g., theair filter device can be provided in kit form to a user). In otherembodiments, portions or an entirety of the expansion unit is assembledto the air filter unit prior to delivery to a user. Regardless, the airfilter devices of the present disclosure are useful with a wide varietyof differently size air handling devices, able to readily fit and sealwith a compartment of the air handling device via the expansion unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a perspective view of an air filter device in accordance withprinciples of the present disclosure, including portions shown in blockform;

FIG. 2A is a perspective view of the air filter device of FIG. 1 in aninitial state;

FIGS. 2B-2D are perspective views of the air filter device of FIG. 1 invarious expanded states;

FIG. 3A is a perspective view of a filter media assembly useful with theair filter device of FIG. 1A;

FIG. 3B is a side view of a portion of the filter media assembly of FIG.3A;

FIG. 4A is a perspective view of an air filter device in accordance withprinciples of the present disclosure;

FIG. 4B is an enlarged view of a portion of the air filter device ofFIG. 4A;

FIG. 5A is a perspective view of an air filter device in accordance withprinciples of the present disclosure;

FIG. 5B is an enlarged view of a portion of the air filter device ofFIG. 5A;

FIG. 6A is a perspective view of an air filter device in accordance withprinciples of the present disclosure;

FIG. 6B is an enlarged view of a portion of the air filter device ofFIG. 6A;

FIG. 7A is a perspective view of an air filter device in accordance withprinciples of the present disclosure;

FIG. 7B is an enlarged view of a portion of the air filter device ofFIG. 7A;

FIG. 8A is a perspective view of an air filter device in accordance withprinciples of the present disclosure;

FIG. 8B is an enlarged view of a portion of the air filter device ofFIG. 8A;

FIG. 9A is a perspective view of an air filter device in accordance withprinciples of the present disclosure;

FIG. 9B is an enlarged view of a portion of the air filter device ofFIG. 9A;

FIG. 10A is a perspective view of an air filter device in accordancewith principles of the present disclosure; and

FIG. 10B is an enlarged view of a portion of the air filter device ofFIG. 10A.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to air filter devices thatreadily fit, and achieve a desired seal within, differently-sized airhandling compartments. One embodiment of an air filter device 20 inaccordance with principles of the present disclosure is shown in FIG. 1and includes an air filter unit 22 and an expansion unit 24 (shown inblock form). The air filter unit 22 can be akin to any conventional orknown air filter (e.g., HVAC air filter), and includes a filter mediaassembly 30 and an outer frame assembly 32 as described below. The outerframe assembly 32 can establish exterior dimensions of the air filterunit 22, including exterior dimensions in length L, width W, and depth Ddirections. The expansion unit 24 can assume a wide variety of forms asdescribed below, and generally serves to selectively increase afootprint or size of the air filter unit 22 in one or more of the lengthL, width W and depth D directions. The air filter device 20 is generallyconstructed to have an initial state as initially provided to a user inwhich some or all of the expansion unit 24 is separate from the airfilter unit 22, or, if connected to the air filter unit 22 in theinitial state, the expansion unit 24 (or corresponding portions thereof)is retracted so as to not overtly extend outside the footprintestablished by the outer frame assembly 32. FIG. 2A is a non-limitingexample of the initial state of the air filter device 20 in which aportion or entirety of the expansion unit 24 (FIG. 1) is apart from theair filter unit 22, and the air filter unit 22 alone (or with theoptional portion of the expansion unit 24 in a retracted arrangement)serves as the air filter device 20 for installation to an air handlingsystem (not shown). In the initial state, then, the air filter device 20has length L_(I), width W_(I) and depth D_(I) dimensions as dictated bythe air filter unit 22, for example by the outer frame assembly 32.Where desired by a user, the expansion unit 24 can be installed and/ordeployed relative to the air filter unit 22, to generate an expandedstate of the air filter device 20. The air filter device 20 can beinstalled to an air handling system in the expanded state (and/or becaused to transition to the expanded state following installation). Asgenerally reflected by the non-limiting example expanded states of FIGS.2B-2D, the expanded state of the air filter device 20 of the presentdisclosure can include an expanded length L_(E) (FIG. 2B), an expandedwidth W_(E) (FIG. 2C) and/or an expanded depth D_(E) (FIG. 2D) that isgreater than the corresponding dimension L_(I), W_(I), D_(I) in theinitial state.

Returning to FIG. 1, in some embodiments, the air filter unit 22 issized for installation to a conventional HVAC system, with at least theouter frame assembly 32 supporting the filter media assembly 30 in thepresence of HVAC system airflow. With these non-limiting constructions,depending upon a size of the air filter compartment provided with theHVAC system, a user can install the air filter unit 22 alone (i.e., theair filter device 20 in the initial state as described above), or canutilize the expansion unit 24 to expand the air filter device 20 in oneor more directions to better match an actual size of the air filtercompartment, better ensuring a desired seal is achieved between the airfilter device 20 and framework of the compartment.

With embodiments in which the initial state of the air filter device 20includes a portion or an entirety of the expansion unit 24 not directlyattached or connected to the air filter unit 22, the air filter device20 can optionally be provided to a user in kit form. For example, theair filter unit 22 and the expansion unit 24 can be commonly packagedwithin a container or other packaging, optionally with one or moreadditional items such as written instructions for use. The packaging canassume any useful format, for example packaging useful for retaildisplay and sale.

Air Filter Unit

The air filter unit 22 can assume various forms, and can include thefilter media assembly 30 and the outer frame assembly 32. The filtermedia assembly 30 can assume a wide variety of forms useful for airfiltration, such as HVAC air filtration, presently known, or in thefuture developed. In some embodiments, the filter media assembly 30 is apleated filter media assembly. By “pleated” is meant a web at least aportion of which has been folded to form a configuration comprising rowsof generally parallel, oppositely oriented folds. For example, and asshown in FIGS. 3A and 3B, a pleated version of the filter media assembly30 includes a plurality of pleats 40 each including a fold line 42defining a pleat tip 44 and a pair of adjacent panels 46.

The pleated version of the filter media assembly 30 can consist of apleated filter media or web 60 alone (as in the illustrated embodiment),or can include one or more additional components or structures appliedor assembled to a pleated filter media 60. The pleated filter media 60of the assembly 30 can be self-supporting or non-self-supporting. Asused herein, the term “self-supporting filter media or web” can describeat least one of the following conditions: (1) a filter media or web thatis deformation resistant without requiring stiffening layers, adhesiveor other reinforcement in the filter media web; or (2) the filter mediagenerally maintains its shape when subjected to an airstream asdescribed, for example, in U.S. Pat. No. 7,169,202 to Kubokawa, theentire teachings of which are incorporated herein by reference; or (3) aweb or media having sufficient coherency and strength so as to bedrapable and handleable without substantial tearing or rupture. As usedherein, the term “non-self-supporting” can denote an air filter mediathat is not capable, in the absence of a support frame and/or a supportgrill, of withstanding the forces encountered due to typical air flow.For example, where the pleated version of the filter media assembly 30consists of the pleated filter media 60 alone, the pleated filter mediaor web 60 can be self-supporting or non-self-supporting. Where thepleated version of the filter media assembly 30 consists of the pleatedfilter media or web 60 and a support structure, the pleated filter media60 can be non-self-supporting with the additional supporting structurerendering the pleated filter media assembly 30, as a whole, to beself-supporting.

The particular filter media 60 selected for the pleated version of thefilter media assembly 30 is not critical to the present disclosure solong as the resultant pleated filter media assembly 30 (whetherconsisting solely of the pleated filter media 60 alone or withadditional structures applied thereto) has the desired characteristicsdescribed herein. The filter media 60 can be constructed, for example,from nonwoven fibrous media formed of thermoplastics or thermosettingmaterials such as polypropylene, linear polyethylene and polyvinylchloride. Other suitable, non-limiting materials for the filter mediainclude porous foams, nonwovens, papers, fiberglass, or the like. Thefilter media assembly 30 can optionally include a highly open wire meshor screen, one or more adhesive strands, etc., that is bonded to thefilter media 60 in order to enhance the pleatability thereof and that ispleated along with the filter media 60 itself. The wire mesh or screen(or other additional component) may impede re-collapsing of the pleatedversion of the filter media assembly 30. In other embodiments, thepleated version of the filter media assembly 30 can incorporatewire-supported pleats, self-supported mini-pleats, or other pleatconstructions currently available or in the future developed.

In some embodiments, the filter media 60 comprises a nonwoven web thatcan have random fiber arrangement and generally isotropic in-planephysical properties (e.g., tensile strength), or if desired may havealigned fiber construction (e.g., one in which the fibers are aligned inthe machine direction as described in U.S. Pat. No. 6,858,297 to Shah etal., the teachings of which are incorporated herein by reference) andanisotropic in-plane physical properties. Some or all of the fiberscomprising the nonwoven webs useful with the filter media 60 can bemulticomponent fibers having at least a first region and a secondregion, where the first region has a melting temperature lower than thesecond region. Some suitable multicomponent fibers are described, forexample, in U.S. Pat. Nos. 7,695,660, 6,057,256, 5,597,645, 5,972,808,5,662,728 and 5,486,410 the teachings of each of which are incorporatedherein by reference in their entireties.

Other nonwoven webs useful with the filter media 60 can be a high loftspunbond web, such as described, for example, in U.S. Pat. No. 8,162,153to Fox et al., the entire teachings of which are incorporated herein byreference. In other embodiments, the filter media 60 can be a low loftspunbond web, such as those described in U.S. Pat. No. 7,947,142 to Foxet al., the entire teachings of which are incorporated herein byreference. In yet other embodiments, nonwoven webs useful with thefilter media 60 are generated by other techniques and/or have othercharacteristics, such as the meltblown nonwoven webs disclosed in U.S.Pat. No. 6,858,297 to Shah et al. (mentioned above). Other non-limitingexample of useful nonwoven web formats include bi-modal fiber diametermeltblown media such as that described in U.S. Pat. No. 7,858,163, theentire teaching of which are incorporated herein by reference.

In some embodiments, an electrostatic charge is optionally imparted intoor on to material(s) of the filter media 60. Thus, the filter media 60can be an electret nonwoven web. Electric charge can be imparted to thefilter media 60 in a variety of ways as is well known in the art, forexample by hydrocharging, corona charging, etc. (e.g., as described inU.S. Pat. No. 7,947,142 (mentioned above)). In other embodiments, thefilter media 60 is not electrostatically charged.

The optional pleats can be formed in the filter media 60 (or in thepleated filter media assembly 30) using various methods and componentsas are well known in the art, e.g., to form a pleated filter for use inapplications such as air filtration, for example those described in U.S.Pat. No. 6,740,137 to Kubokawa et al. and U.S. Pat. No. 7,622,063 toSundet et al., the entire teachings of both of which are incorporatedherein by reference.

With pleated versions of the filter media assembly 30, a variety ofpleat depths D can be incorporated. In some embodiments, the pleatedfilter media assembly 30 has a pleat depth D of at least about 4 inches,optionally not less than 4 inches (e.g., a “deep pleat” pleated filtermedia). Other depths, greater or smaller, are also acceptable.

In other embodiments of the present disclosure, portions or all of thefilter media assembly 30 need not have a pleated construction.

Regardless of an exact construction, the filter media assembly 30defines opposing, first and second major faces 70, 72 (referencedgenerally in FIGS. 3A and 3B). Further, a perimeter of the filter mediaassembly can be defined by opposing, first and second side edges 80, 82,and opposing, first and second end edges 84, 86. In some embodiments,the perimeter can have the rectangular shape (that is specificallyinclusive of a square shape) shown.

Returning to FIG. 1, the outer frame assembly 32 can assume a variety offorms and is generally configured to surround the perimeter of thefilter media assembly 30. Further, the outer frame assembly 32 isconstructed to robustly support the filter media assembly 30 in theinitial state as well as in any of the expanded states described below,including the outer frame assembly 32 rigidly maintaining theestablished length L_(I), width W_(I), and depth D_(I) (FIG. 2A)dimensions when subjected to expected forces of a designated end-useenvironment (e.g., the outer frame assembly 32 will maintain itsstructural integrity with installation to an HVAC system air filtercompartment and subjecting the air filter device 20 to normal HVACsystem airflow). With this in mind, the outer frame assembly 32 includesor defines opposing, first and second side frame structures 100 (one ofwhich is visible in FIG. 1) and opposing, first and second end framestructures 104 (one of which is visible in FIG. 1). The side framestructures 100 are generally configured to cover a respective one of thefirst and second side edges 80, 82 (FIG. 3A) of the filter mediaassembly 30, whereas the end frame structures 104 are generallyconfigured to cover a respective one of the first and second end edges84, 68 (FIG. 3A).

The frame structures 100, 104 can have any format conducive to use aspart of the outer frame assembly 32, and in some embodiments can besubstantially identical. For example, in some embodiments, one or moreor all of the frame structures 100, 104 can consist of a single framemember or body. In other embodiments, one or more or all of the framestructures 100, 104 can include two or more frame members that connectedto another (e.g., slidably connected).

The outer frame assembly 32 can be formed from a variety of materialscapable of maintaining their structural integrity in the presence ofexpected forces. For example, the outer frame assembly 32 can beconstructed of cardboard, paperboard, plastic, metal, etc. In someembodiments, the outer frame assembly 32 integrally forms the side andend frame structures 100, 104. Thus, in some embodiments a major portionof the outer frame assembly 32 may be conveniently formed by the foldingof a suitable precursor material (e.g., paperboard) along fold lines soas to provide the side and end frame structures 100, 104. However, anysuitable frame construction may be used; i.e. any major portion of theouter frame assembly 32 may be made of any suitable material (whetherpaperboard, plastic, etc.) and may be formed e.g. by folding of a singleframe piece, by the assembling of multiple pieces to each other, and soon. In many embodiments, all four major frame structures 100, 104 mayeach comprise upstream and downstream flanges and inner and outersidewalls/panels and foldable connections there between.

In some embodiments, the air filter unit 22 can further include one ormore grid or grill structures extending over a corresponding one of themajor faces 70, 72 (FIGS. 3A and 3B) of the filter media assembly 30.For example, FIG. 1 illustrates a grid or grill 120 projecting from theouter frame assembly 32 and extending over the first major face 70 (bestidentified in FIG. 3B) of the filter media assembly 30. The patternreflected by FIG. 1 for the grid or grill 120 is but one acceptableconfiguration. The air filter unit 22 can optionally include anadditional grill or grid structure (not shown) overlying the secondmajor face 72 (hidden in FIG. 1, but identified, for example, in FIG.3B) of the filter media assembly 30. Regardless, the grill(s) or grid(s)120 can be formed of a material similar to that of the outer frameassembly 32. In some embodiments, the grill(s) or grid(s) 120 can beintegrally formed with, and folded relative to, the outer frame assembly32. In other embodiments, the grill(s) or grid(s) (or sub-componentsthereof) can be separately formed and subsequently attached to the outerframe assembly 32.

Expansion Unit

The expansion unit 24 can assume a variety of forms compatible with theparticular format of the air filter unit 22. One or more portions of, oran entirety of, the expansion unit 24 can be provided as component of(e.g., pre-assembled to) the air filter unit 22; in other embodiments,an entirety of the expansion unit 24 can be provided apart from the airfilter unit 22 and subsequently assembled thereto by a user. Variousexamples of expansion units in accordance with principles of the presentdisclosure are described below. While described separately, portions oran entirety of one example expansion unit can be combined with portionsor an entirety of another example expansion unit.

An air filter device 220 including an example expansion unit 224(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 4A and4B. As a point of reference, FIGS. 4A and 4B reflect a possibleinstallation condition of the air filter device 220 in which theexpansion unit 224 (or portions thereof) has been mounted to the airfilter unit 22. Conversely, a possible delivery condition (not shown) ofthe air filter device 220 includes the expansion unit 224 not yetmounted to the air filter unit 22 (e.g., a user can receive the airfilter device 220 in the delivery condition, and then mount theexpansion unit 224 (or portions thereof) to the air filter unit 22 inachieving the possible installation condition).

The expansion unit 224 includes one or more standoffs 230. The standoffs230 are generally sized and shaped for mounting to a designated regionof the air filter unit 22, and can include one or more of a lengthstandoff 230A, a width standoff 230B, and a depth standoff 230C. Thelength standoff 230A is generally sized and shaped for mounting to oneof the end frame structures 104 to effectuate an expanded state lengthL_(E) that is greater than the initial state length L_(I) (FIG. 1). Thewidth standoff 230B is generally sized and shaped for mounting to one ofthe side frame structures 100 to effectuate an expanded state widthW_(E) in the air filter device that is greater than the initial statewidth W_(I) (FIG. 1). Finally, the depth standoff 230C is generallysized and shaped for mounting to outer frame assembly 32 or othercomponent of the air filter unit 22 at a location that does not overtlyimpede airflow through the air filter unit 22 (e.g., at a corner formedby two of the frame structures 100, 104, on the grill or grid 120, etc.)to effectuate an expanded state depth D_(E) that is greater than theinitial state depth D_(I) (FIG. 1). In some embodiments, the expansionunit 224 as provided to a user in the delivery condition mentioned abovecan include one (or more) of the length standoff 230A, one (or more) ofthe width standoff 230B, and a plurality of the depth standoffs 230C. Inother embodiments, the expansion unit 224 as provided to a user in thedelivery condition can include less than all of the length standoff230A, the width standoff 230B and/or the depth standoffs 230C (e.g., theexpansion unit can include only the depth standoffs 230C).

Each of the standoffs 230 can have a similar construction, for exampleincluding a standoff body 240 (identified, for example, for the lengthstandoff 230A in FIG. 4B). In some embodiments, the standoff body 240can be formed of a light weight, resilient, at least slightlycompressible material capable of maintaining a designated shape whensubjected to compression. For example, the standoff body 240 can be afoam material (e.g., open or closed cell foams, natural foams, syntheticfoams, etc.). Other materials, such as rubber, plastic, etc., are alsoenvisioned. In some embodiments, the standoff body 240 associated witheach of the standoffs 230A-230C is a pre-cut foam strip (e.g., as withthe standoffs 230A, 230B) or block (e.g., a cylindrical block as withthe standoffs 230C), sized and shaped in accordance with geometries ofthe corresponding air filter unit 22 as described above.

Each of the standoffs 230 can further be configured to promote mountingthereof to the air filter unit 22 by a user. For example, a face of thestandoff body 240 can carry (e.g., be coated with) an adhesiveformulated to achieve a bond between the standoff body 240 and acorresponding portion of the air filter unit 22 (e.g., where the outerframe assembly 32 is a paperboard material, the selected adhesive can beformulated to achieve a bond with paperboard). As initially provided toa user (e.g., as part of a kit in which the standoff(s) 230 are providedto a user apart from the air filter unit 22), a release liner canfurther be included, temporarily covering the adhesive. When the user isready to mount the standoff 230 to the air filter unit 22, the releaseliner is removed thereby exposing the adhesive. In other embodiments,one or more adhesive strips (not shown) can be provided on the outerframe assembly 32 (or other exterior components of the air filter unit22) at location(s) corresponding with potential application of astandoff 230; under these circumstances, the adhesive strip(s) can betemporarily covered by a release liner that is removed prior to mountingof the corresponding standoff 230. In yet other embodiments, a strip ofdouble sided tape (that may be provided to the user as part of theexpansion unit 224) can be employed to secure the standoff(s) 230 to theair filter unit 22. Other configurations that facilitate mounting of thestandoff 230 to the air filter unit 22 are also acceptable (e.g., amechanical fastener, hook-and-loop fasteners, etc.).

During use, the air filter device 220 is initially provided to a user inan initial state in which the air filter unit 22 is separated from theexpansion unit 224. For example, the air filter unit 22 and theexpansion unit 224 can be provided to a user in a common packaging, withnone of the standoffs 230 mounted to the air filter unit 22.Alternatively, a user can obtain (e.g., purchase) the air filter unit 22and the expansion unit 224 separately. Regardless, the user thenevaluates (e.g., visually estimates) dimensions of the air filtercompartment (not shown) to which the air filter device 220 will beinstalled. In some instances, dimensions of the air filter unit 22 willclosely correspond to the dimensions of the air filter compartment.Under these circumstances, the air filter unit 22 alone can be installedto the air filter compartment (e.g., the air filter unit 22 serves asthe installed air filter device 220). In other instances, the user maydetermine that one or more of the length L_(I), width W_(I) and/or depthD_(I) (FIG. 2A) dimension of the air filter unit 22 is appreciably less(e.g., 10% less) than the corresponding dimension of the air filtercompartment. Under these circumstances, the user can select and mountone or more of the standoffs 230 to air filter unit 22, effectuating adesired increase in the corresponding dimension. For example, if it isdetermined that the depth D_(I) of the air filter unit 22 is appreciableless than the depth dimension of the air filter compartment, one or moreof the depth standoffs 230C can be mounted to the air filter unit 22 asshown, for example, in FIG. 4A. Additionally or alternatively, thelength standoff 230A can be selected and mounted to the air filter unit22 to effectuate an increased or expanded length L_(E), and the widthstandoff 230B can be selected to the air filter unit 22 to effectuate anincreased or expanded width W_(E). It will be understood that for aparticular air filter compartment installation, less than all of thestandoffs 230A-230C may be required. Once the selected standoff(s) 230have been mounted to the air filter unit 22 so as to transition the airfilter device 220 to an expanded state, the air filter device 220 can beinstalled to the air filter compartment, with the mounted standoff(s)230 bearing against framework of the air filter compartment andpromoting a seal between the air filter device 220 and the air filtercompartment.

Another air filter device 320 including an example expansion unit 324(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 5A and5B. As a point of reference, FIGS. 5A and 5B reflect a possibleinstallation condition of the air filter device 320 in which theexpansion unit 324 (or portions thereof) has been mounted to the airfilter unit 22. Conversely, a possible delivery condition (not shown) ofthe air filter device 320 includes the expansion unit 324 not yetmounted to the air filter unit 22 (e.g., a user can receive the airfilter device 320 in the delivery condition, and then mount theexpansion unit 324 (or portions thereof) to the air filter unit 22 inachieving the possible installation condition). In yet otherembodiments, the delivery condition of the air filter device 320includes the expansion unit 324 (or portions thereof) pre-assembled to(or integrally formed by) the air filter unit 22. With some of theseembodiments, the pre-assembled expansion unit 324 (or portions thereof)is configured to self-deploy to the expanded condition reflected byFIGS. 5A and 5B in the presence of airflow as described below.

The expansion unit 324 includes one or more flanges 330. The flanges 330are generally sized and shaped in accordance with a designated region ofthe air filter unit 22, and can include one or more of a length flange330A and one or more of a width flange 330B. The length flange 330A isgenerally sized and shaped in accordance with dimensions of one of theend frame structures 104 to effectuate an expanded state length L_(E)that is greater than the initial state length L_(I) (FIG. 1). The widthflange 330B is generally sized and shaped in accordance with dimensionsof one of the side frame structures 100, 102 to effectuate an expandedstate width W_(E) that is greater than the initial state width W_(I)(FIG. 1). In some embodiments, the expansion unit 324 can include bothof the length and width flanges 330A, 330B; in other embodiments, theexpansion unit 324 includes only the length flange 330A or only thewidth flange 330B.

Apart from dimensions, each of the flanges 330 can have a similarconstruction. For example, and as identified for the length flange 330Ain FIG. 5B, each of the flanges 330 can be a lightweight yet relativestiff material defining a fixed end 340 opposite a free end 342. Thefixed end 340 can be connected to, or is configured for connection to bya user, the corresponding frame structure of the air filter unit 22(e.g., the fixed end 340 of the length flange 330A is connected to thefend frame structure 104) in a manner permitting pivoting movement atthe point or line of connection. The flange 330 projects away from thefixed end 340, terminating at the free end 342 that is otherwise free ofdirect connection or attachment to the air filter unit 22. For example,in some embodiments the flange 330 is a paperboard body integrallyformed with the outer frame assembly 32, with a fold line being formedat the line of interface between the flange 330 and the correspondingframe structure 100, 104 of the outer frame assembly 32 to define thefixed end 340.

With embodiments in which the air filter device 320 is provided to auser with the flange(s) 330 pre-assembled to (e.g., integrally formedwith) the air filter unit 22, the user installs the air filter device320 (including the flange(s) 330) to the air filter compartment (notshown). With embodiments in which the air filter device 320 is providedto a user with the flange(s) 330 uncoupled from the air filter unit 22,the user can first compare an estimated size of the air filtercompartment with the length and width L_(I), W_(I) dimensions of the airfilter unit 22. Based on this comparison, one or both of the flanges330A, 330B can be mounted to the air filter unit 22 as described above,with the so-configured air filter device 320 then being installed to theair filter compartment. In either instance, the air filter device 320can be installed such that the free end 342 of the flange(s) 330 facesthe upstream direction of airflow through the air filter compartment.During operation of the air handling device, airflow (designated byarrow F in FIG. 5A) will interface between the flange(s) 330 and theouter frame assembly 32, forcing the flange(s) 330 to extend outwardlyrelative to the outer frame assembly 32 (e.g., the flange(s) 330 iscaused to pivot relative to the outer frame assembly 32 at the fixed end340, with the corresponding free end 342 moving outwardly away from theouter frame assembly 32). In this expanded state, the flange(s) 330 canbe brought into contact with framework of the air filter compartment,promoting a seal between the air filter device 320 and the air filtercompartment.

Another air filter device 420 including an example expansion unit 424(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 6A and6B. As a point of reference, FIGS. 6A and 6B reflect a possibleinstallation condition of the air filter device 420 in which theexpansion unit 424 (or portions thereof) has been mounted to the airfilter unit 22. Conversely, a possible delivery condition (not shown) ofthe air filter device 420 includes the expansion unit 424 (or portionsthereof) not yet mounted to the air filter unit 22 (e.g., a user canreceive the air filter device 420 in the delivery condition, and thenmount the expansion unit 424 (or portions thereof) to the air filterunit 22 in achieving the possible installation condition). In yet otherembodiments, the delivery condition of the air filter device 420includes the expansion unit 424 (or portions thereof) pre-assembled to(or integrally formed by) the air filter unit 22. With some of theseembodiments, the pre-assembled expansion unit 424 (or portions thereof)is configured to self-deploy to the expanded condition reflected byFIGS. 6A and 6B, optionally in the presence of airflow as describedbelow.

The expansion unit 424 can be akin to the expansion unit 324 (FIGS. 5Aand 5B) described above, and includes one or more the flanges 330 (e.g.,the length flange 330A and the width flange 330B). In addition, theexpansion unit 424 includes one or more deflection bodies 430 associatedwith a corresponding one of the flanges 330 (e.g., with the non-limitingexample of FIGS. 6A and 6B, the expansion unit 424 includes a firstdeflection body 430A corresponding with the length flange 330A and asecond deflection body 430B corresponding with the width flange 330B).Apart from dimensions, each of the deflection bodies 430 can have asimilar construction. For example, each of the deflection bodies 430 canbe formed of a light weight, resilient, at least slightly compressiblematerial capable of maintaining a designated shape when subjected tocompression. In some embodiments, the deflection bodies 430 can be afoam material (e.g., open or closed cell foams, natural foams, syntheticfoams, etc.). Other materials, such as rubber, plastic, etc., are alsoenvisioned. In some embodiments, the deflection bodies 430 can each be apre-cut foam strip, sized and shaped in accordance with geometries ofthe corresponding air filter unit 22 components (e.g., the firstdeflection body 430A is pre-cut to a size and shape corresponding withdimensions of one of the end frame structures 104; the second deflectionbody 430B is pre-cut to a size and shape corresponding with dimensionsof one of the side frame structures 100).

In some embodiments, the air filter device 420 is provided to a userwith the deflection bodies 430 pre-assembled to the air filter unit 22.In other embodiments, the delivery condition of the air filter device420 can include the deflection bodies 430 apart from the air filter unit22 (it being recalled that the flanges 330 may or may not be assembledto the air filter unit 22 in the delivery condition). With theseconfigurations, the expansion unit 424 can further include one or morestrips of double-sided adhesive tape or other fastening devices (e.g.,complimentary strips of hook-and-loop fasteners) that are employed by auser to secure the deflection bodies 430 at the locations shown.Alternatively, the deflection bodies 430 can be coated with an adhesivethat is temporarily covered by a release liner, the air filter unit 22can be coated with an adhesive at desired locations and that aretemporarily covered by a release liner, etc.

With embodiments in which the air filter device 420 is provided to auser with the flange(s) 330 and the deflection body/bodies 430pre-assembled to the air filter unit 22, the user installs the airfilter device 420 to the air filter compartment (not shown). Withembodiments in which the air filter device 320 is provided to a userwith the deflection body/bodies 430 uncoupled from the air filter unit22, the user can first compare an estimated size of the air filtercompartment with the length and width L_(I), W_(I) dimensions of the airfilter unit 22. Based on this comparison, one or both of the deflectionbodies 430A, 430B can be mounted to the air filter unit 22 as describedabove, with the so-configured air filter device 420 then being installedto the air filter compartment. In either instance, the air filter device420 can be installed such that the free end 342 of the flange(s) 330A,330B faces the upstream direction of airflow through the air filtercompartment. During operation of the air handling device, airflow(designated by arrow F in FIG. 6A) will progress between each of theflanges 330A, 330B and the outer frame assembly 32, forcing theflange(s) 330 to extend outwardly relative to the outer frame assembly32 as described above. The deflection body (where provided) 430 biasesthe corresponding flange 330 such that the free end 342 projects awayfrom the outer frame assembly 32, and prevents the corresponding flange330A, 330B from collapsing on to the outer frame assembly 32. Onceagain, in this expanded state, the flange(s) 330A, 330B can be broughtinto contact with framework of the air filter compartment, promoting aseal between the air filter device 420 and the air filter compartment.

Another air filter device 520 including an example expansion unit 524(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 7A and7B. As a point of reference, FIGS. 7A and 7B reflect a possibleinstallation condition of the air filter device 520 in which theexpansion unit 524 (or portions thereof) has been mounted to the airfilter unit 22. Conversely, a possible delivery condition (not shown) ofthe air filter device 520 includes the expansion unit 524 not yetmounted to the air filter unit 22 (e.g., a user can receive the airfilter device 520 in the delivery condition, and then mount theexpansion unit 524 (or portions thereof) to the air filter unit 22 inachieving the possible installation condition). In yet otherembodiments, the delivery condition of the air filter device 520includes the expansion unit 524 (or portions thereof) pre-assembled to(or integrally formed by) the air filter unit 22. With some of theseembodiments, the pre-assembled expansion unit 524 (or portions thereof)is configured to self-deploy to the expanded condition reflected byFIGS. 7A and 7B in the presence of airflow as described below.

The expansion unit 524 includes one or more flanges 530 that can be akinto the flanges 330 (FIG. 5A) described above. The flanges 530 aregenerally sized and shaped in accordance with a designated region of theair filter unit 22, and can include one or more of a length flange 530Aand one or more of a width flange 530B. The length flange 530A isgenerally sized and shaped in accordance with dimensions of one of theend frame structures 104 to effectuate an expanded state length L_(E)(not specifically identified in FIGS. 7A and 7B for ease ofillustration) that is greater than the initial state length L_(I) (FIG.1). The width flange 530B is generally sized and shaped in accordancewith dimensions of one of the side frame structures 100 to effectuate anexpanded state width W_(E) (not specifically identified in FIGS. 7A and7B for ease of illustration) that is greater than the initial statewidth W_(I) (FIG. 1). In some embodiments, the expansion unit 524 caninclude both of the length and width flanges 530A, 530B; in otherembodiments, the expansion unit 524 includes only the length flange 530Aor only the width flange 530B.

Apart from dimensions, each of the flanges 530 can have a similarconstruction. For example, each of the flanges 530 can be a lightweightyet relative stiff material. As identified in FIG. 7B for the widthflange 530B, each of the flanges 530 can define a fixed end 540 oppositea free end 542. Further, a fold line 544 can be formed intermediate theends 540, 542. With this construction, the flange 530 can be viewed hashaving or defining a first portion 546 between the fixed end and thefold line 544, and a second portion 548 between the fold line 544 andthe free end 542. The fixed end 540 can be connected to, or isconfigured for connection to be a user, the corresponding framestructure of the air filter unit 22 (e.g., the fixed end 540 of thewidth flange 530B is connected to the side frame structure 100) in amanner permitting pivoting movement at the point or line of connection.For example, in some embodiments the flange 530 is a paperboard bodyintegrally formed with the outer frame assembly 32, with a fold linebeing formed at the line of interface between the flange 530 and thecorresponding frame structure 100, 104 of the outer frame assembly 32 todefine the fixed end 540 as described above. The fold line 544 arrangesthe first and second portions 546, 548 in differing spatialorientations. For example, with the non-limiting example of FIGS. 7A and7B, the second portion 548 extends over or overlaps the first portion546. Other spatial arrangements are also envisioned, and in otherembodiments, two or more fold lines can be formed along thecorresponding flange 530.

With embodiments in which the air filter device 520 is provided to auser with the flange(s) 530 pre-assembled to (e.g., integrally formedwith) the air filter unit 22 and pre-folded to arrangement shown inFIGS. 7A and 7B, the user installs the air filter device 520 (includingthe flange(s) 530) to the air filter compartment (not shown). Withembodiments in which the air filter device 520 is provided to a userwith the flange(s) 530 either uncoupled from the air filter unit 22 orpre-assembled to the air filter unit 22 but not fully folded (e.g., thefold line 544 can be imparted into the flange 530, but the secondportion 548 is not completely folded relative to the first portion 546),the user can first compare an estimated size of the air filtercompartment with the length and width L_(I), W_(I) dimensions of the airfilter unit 22. Based on this comparison, one or both of the flanges530A, 530B can be mounted to the air filter unit 22 as described aboveand then folded at the corresponding fold line 544 (or, if pre-assembledbut not yet folded, the selected flange(s) 530A, 530B can then befolded), with the so-configured air filter device 520 then beinginstalled to the air filter compartment. In either instance, the airfilter device 520 can be installed such that the fixed end 540 of theflange(s) 530 is opposite of the upstream direction of airflow throughthe air filter compartment. During operation of the air handling device,airflow (designated by arrow F in FIG. 7A) will interface between theflange(s) 530 and the outer frame assembly 32, forcing the flange(s) 530to extend outwardly relative to the outer frame assembly 32 (e.g., theflange(s) 530 is caused to pivot relative to the outer frame assembly 32at the fixed end 540, with the corresponding free end 542 movingoutwardly away from the outer frame assembly 32). In this expandedstate, the flange(s) 530 can be forced into contact with framework ofthe air filter compartment, promoting a seal between the air filterdevice 520 and the air filter compartment. The folded arrangement of theflange(s) 530 better ensures contact between the free end 542 (and otherregions of the flange 530) and the air filter compartment framework.

Another air filter device 620 including an example expansion unit 624(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 8A and8B. As a point of reference, the expansion unit 624 can be pre-assembledto the air filter unit 22 in a delivery condition of the air filterdevice 620. FIGS. 8A and 8B reflect a possible expanded state of the airfilter device 620.

The expansion unit 624 includes at least one flange 630 that can begenerally akin to the flanges 330 (FIG. 5A) described above. The flange630 is generally sized and shaped in accordance with a designated regionof the air filter unit 22, such as dimensions of one of the end framestructures 104 or one of the side frame structures 100. For example,FIGS. 8A and 8B illustrate the flange 630 as being associated with theend frame structure 104. Alternatively, the flange 630 can be associatedwith one of the side frame structures 100. In yet other embodiments, theexpansion unit 624 can include two (or more of flanges 630), such as aflange at each of the side frame structures 100, a flange at each of theend frame structures 104, a first flange at one of the side framestructures 100 and a second flange at one of the end frame structures104, etc.

The flange 630 can include a main panel 640 and locking tabs 642, 644.The main panel 640 is sized and shaped in accordance with dimensions ofthe corresponding frame structure 100, 104. The locking tabs 642, 644extend from opposing side edges of the main panel 640. In otherembodiments, a single one of the tabs 642 or 644 is included. The mainpanel 640 defines a fixed end 650 opposite a free end 652. The fixed end650 can be connected to, or is configured for connection to by a user,the corresponding frame structure of the air filter unit 22 (e.g., thefixed end 650 is connected to the end frame structure 104) in a mannerpermitting pivoting movement at the point or line of connection. Thepanel 640 projects away from the fixed end 650, terminating at the freeend 652 that is otherwise free of direct connection or attachment to theair filter unit 22. For example, in some embodiments the flange 630 is apaperboard body integrally formed with the outer frame assembly 32, witha fold line being formed at the line of interface between the main panel640 and the corresponding frame structure 100. 104 of the outer frameassembly 32 to define the fixed end 650, and additional fold linesdefining the locking tabs 642, 644 relative to the main panel 640.

The locking tabs 642, 644 are configured to selectively lock the flange630 relative to the air filter unit 22 at a desired spatial orientation.For example, each of the locking tabs 642, 644 can form or define a tabend 660 projecting from a shoulder 662 as identified for the locking tab642 in FIG. 8B. The tab end 660 is sized for insertion within one ormore locking slots 664 formed in the outer frame assembly 32. Uponinsertion, the shoulder 662 bears against a structure of the outer frameassembly 32, with this interface preventing the flange 630 fromcollapsing on to the outer frame assembly 32. In some embodiments, aplurality of the locking slots 664 are provided, with the locking slots664 being arranged in a spaced apart manner to provide differing spatialorientations of the flange 630 relative to the outer frame assembly 32,and thus a range of available including spacings between the free end652 and the outer frame assembly 32. The locking slots 664 can be formedin various manners (e.g., slits, cuts, perforations, etc. through athickness of the corresponding frame structure of the outer frameassembly 32), and may or may not be complete cuts in the initial state(e.g., to the extent a user desires to employ a selected one of thelocking slots 664, the selected locking slot 664 can first be“completed” by the user). Other locking mechanisms or techniques arealso acceptable that may or may not entail the locking slots 664; forexample, an adhesive can be provided along a face of the locking tabs642, 644.

Use of the air filter device 620 can include the first comparing anestimated size of the air filter compartment with the length and widthL_(I), W_(I) (FIG. 2A) dimensions of the air filter unit 22 for whichone of the flanges 630 is available (e.g., with the non-limiting exampleof FIGS. 8A and 8B, the flange 630 is available to affect an expansionin the length direction). Based on this comparison, the flange 630 canbe arranged to an expanded state corresponding with the estimateddimension by coupling the locking tabs 642, 644 to the outer frameassembly 32 at a desired location (e.g., the locking tabs 642, 644 areconnected to the locking slot 664 appropriate for locating the free end652 at a spatial position that effectuates an expanded length L_(E)corresponding with the estimated length of the air filter compartment).The so-configured air filter device 620 can then be installed to the airfilter compartment, with the free end 652 contacting framework of theair filter compartment to promote a seal between the air filter device620 and the framework. In other instances, the comparison may indicatethat the air filter unit 22 is appropriately sized for installation tothe air filter compartment, in which case the flange 630 is nottransitioned to an expanded stated. Instead, the flange 630 can remaincollapsed against the outer frame assembly 32 with installation of theair filter device 620 to the air filter compartment.

Another air filter device 720 including an example expansion unit 724(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 9A and9B. As a point of reference, the expansion unit 724 can be pre-assembledto the air filter unit 22 in a delivery condition of the air filterdevice 720. The expansion unit 724 can be configured to self-deploy tothe expanded state reflected by FIGS. 9A and 9B in the presence ofairflow as described below.

The expansion unit 724 includes first-fourth flanges 730A-730D. Theflanges 730A-730D can be akin to the flanges 330 (FIG. 5A) describedabove, and are generally sized and shaped in accordance with adesignated region of the air filter unit 22. For example, the first andsecond flanges 730A, 730B are each generally sized and shaped inaccordance with dimensions of one of the end frame structures 104 toeffectuate an expanded state length L_(E) (not specifically identifiedin FIGS. 9A and 9B for ease of illustration) that is greater than theinitial state length L_(I) (FIG. 1). The third and fourth flanges 730C,730D are each generally sized and shaped in accordance with dimensionsof one of the side frame structures 100 to effectuate an expanded statewidth W_(E) (not specifically identified in FIGS. 9A and 9B for ease ofillustration) that is greater than the initial state width W_(I) (FIG.1).

Apart from dimensions, each of the flanges 730A-730D can have a similarconstruction. For example, each of the flanges 730A-730D can be alightweight yet relative stiff material defining a fixed end 740opposite a free end 742 (identified in FIG. 9B for the third flange730C). The fixed end 340 can be connected to the corresponding framestructure of the air filter unit 22 (e.g., the fixed end 740 of thethird flange 730C is connected to the side frame structure 100) in amanner permitting pivoting movement at the point or line of connection.The free end 742 of each of the flanges 730A-730D is free of directconnection or attachment to the air filter unit 22. Finally, acontinuous connection feature 744 (drawn generally in FIGS. 9A and 9B)is established or provided between orthogonally adjacent ones of theflanges 730A-730D that permits pivoting movement of the correspondingflanges while maintaining a continuous obstruction to airflow. Forexample, the first flange 730A and the third flange 730C are orthogonalto one another, and are connected to one another at the connectionfeature 744. The connection feature 744 is configured such that theflanges 730A, 730C can readily transition from a collapsed arrangement(not shown), in which the flanges 730A, 730C are collapsed on to theouter frame assembly 32, to the expanded state shown. The connectionfeature 744 remains intact throughout this transition, presenting acontinuous structure or obstruction to airflow. For example, theconnection feature 744 can include the flanges 730A, 730C providingcomplimentary engagement features, such as a tab-and-slot typeconnection, that permits sliding movement of the flanges 730A, 730Crelative to one another. Alternatively, a series of folds can beimparted into a material defining an interface between the flanges 730A,730C (e.g., akin to origami). In yet other embodiments, a separatecorner piece (not shown) can be assembled to the flanges 730A, 730C indefining the connection feature 744.

In some embodiments the flanges 730A-730D are each a paperboard bodyintegrally formed with the outer frame assembly 32, with a fold linebeing formed at the line of interface between each of the flanges730A-730D and the corresponding frame structure 100, 104 of the outerframe assembly 32 to define the fixed end 740.

During use, the air filter device 720 can be installed such that thefree end 742 of each of the flanges 730A-730D faces the upstreamdirection of airflow through the air filter compartment. Duringoperation of the air handling device, airflow (designated by arrow F inFIG. 9A) will interface between the flanges 730A-73D and the outer frameassembly 32, forcing the flanges 730A-730D to extend outwardly relativeto the outer frame assembly 32 (e.g., the flanges 730A-730D are causedto pivot relative to the outer frame assembly 32 at the correspondingfixed end 740, with the corresponding free end 742 moving outwardly awayfrom the outer frame assembly 32). The expansion unit 724 can optionallybe viewed as self-energizing to the expanded state. In the expandedstate, the flanges 730A-730D can be brought into contact with frameworkof the air filter compartment, promoting a seal between the air filterdevice 720 and the air filter compartment.

Another air filter device 820 including an example expansion unit 824(referenced generally) in accordance with principles of the presentdisclosure applied to the air filter unit 22 is shown in FIGS. 10A and10B. As a point of reference, FIGS. 10A and 10B reflect a possibleexpanded state of the air filter device 820 in which the expansion unit824 has been mounted to the air filter unit 22. Conversely, a possibledelivery condition (not shown) of the air filter device 820 includes theexpansion unit 824 not yet mounted to the air filter unit 22 (e.g., auser can receive the air filter device 820 in the delivery condition,and then mount the expansion unit 824 (or portions thereof) to the airfilter unit 22 in achieving the possible expanded state).

The expansion unit 824 includes one or more seal bodies 830. The sealbodies 830 are generally sized and shaped in accordance with adesignated region of the air filter unit 22, and can includefirst-fourth seal bodies 830A-830D. The first and second seal bodies830A, 830B can each be generally sized and shaped in accordance withdimensions of one of the end frame structures 104 to effectuate anexpanded state length L_(E) (not specifically identified in FIGS. 10Aand 10B for ease of illustration) that is greater than the initial statelength L_(I) (FIG. 1). The third and fourth seal bodies 830C, 830D caneach be generally sized and shaped in accordance with dimensions of oneof the side frame structures 100 to effectuate an expanded state widthW_(E) (not specifically identified in FIGS. 10A and 10B for ease ofillustration) that is greater than the initial state width W_(I) (FIG.1). In other embodiments, the expansion unit 824 can include less thanall of the first-fourth seal bodies 830A-830D.

Apart from dimensions, each of the seal bodies 830 can have a similarconstruction. For example, each of the seal bodies 830 can be formed ofa light weight, resilient, at least slightly compressible materialcapable of maintaining a designated shape when subjected to compression.In some embodiments, the seal bodies 830 can be a foam material (e.g.,open or closed cell foams, natural foams, synthetic foams, etc.). Inrelated embodiments, the seal bodies 830 can be hollow structures. Othermaterials, such as rubber, plastic, etc., are also envisioned. In someembodiments, the seal bodies 830 associated can each be a pre-cut,hollow foam strip, sized and shaped in accordance with geometries of thecorresponding air filter unit 22 components (e.g., the first and secondseal bodies 830A, 830B are both pre-cut to a size and shapecorresponding with dimensions of one of the end frame structures 104;the third and fourth seal bodies 830C, 830D are pre-cut to a size andshape corresponding with dimensions of one of the side frame structures100).

In some embodiments, the air filter device 820 is initially provided toa user with the seal bodies 830A-830D mounted to the air filter unit 22(e.g., via an adhesive or other fastener). In related embodiments, oneor more of the seal bodies 830A-830D are pre-assembled to the air filterunit 22 in a releasable fashion (e.g., a pressure sensitive adhesive)that permits a user to selectively remove one or more of the pre-appliedseal bodies 830A-830D. In yet other embodiments, the delivery conditionof the air filter device 820 can include the seal bodies 830A-830D apartfrom the air filter unit 22. With these configurations, the expansionunit 824 can further include one or more strips of double-sided adhesivetape or other fastening devices (e.g., complimentary strips ofhook-and-loop fasteners) that are employed by a user to secure the sealbodies 830A-830C at the locations shown. Alternatively, the seal bodies830A-830D can be coated with an adhesive that is temporarily covered bya release liner, the air filter unit 22 can be coated with an adhesiveat desired locations and that are temporarily covered by a releaseliner, etc.

With embodiments in which the air filter device 820 is provided to auser with the seal bodies 830A-830D permanently assembled to the airfilter unit 22, the user installs the air filter device 820 to the airfilter compartment (not shown). With embodiments in which the air filterdevice 820 is provided to a user with the seal bodies 830A-830Duncoupled from the air filter unit 22 or with the seal bodies 830A-830Dremovably pre-mounted to the air filter unit 22, the user can firstcompare an estimated size of the air filter compartment with the lengthand width L_(I), W_(I) dimensions of the air filter unit 22. Based onthis comparison, one or more of the seal bodies 830A-830D can be mountedto (or removed from) the air filter unit 22 as described above, with theso-configured air filter device 820 then being installed to the airfilter compartment. With circumstances in which at least one of the sealbodies 830A-830D is mounted to the air filter unit 22 upon installation,the seal body/bodies 830A-830D can be brought into contact withframework of the air filter compartment, promoting a seal between theair filter device 820 and the air filter compartment.

Features or components of two or more of the expansion units 224, 324,424, 524, 624, 724, 824 described above can be combined. For example,any of the expansion units described above can further include at leastthe depth standoffs 230C (FIG. 4A).

Returning to FIG. 1, the air filter devices of the present disclosureare useful in a wide variety of air handling applications. In someembodiments, the air filter device can be configured for use with HVACsystems. With these and other embodiments, a user is afforded theability to custom fit the air filter device 20 (via expansion in one ormore of the length, width, and depth directions L, W, D) to an exactsize of the air filter compartment provided with the user's actual HVACsystem. In related embodiments, the air filter device 20 can be providedas a universal product, appropriate for use with a number of differentHVAC systems that might otherwise have slightly different air filtercompartment dimensions. By way of example, different HVAC systemmanufacturers may each specify to a user that a 16″×20″×4″ air filtershould be used with their HVAC system, yet the actual air filtercompartment is sized and shaped to provide a best fit with slightlydifferent dimensions (e.g., 16″×19″×4″; 16″×21″×4″; 15″×20″×4″;17″×20″×4″; 16″×20″×3.5″; 16″×20″×4.5″; etc.). With this in mind, theair filter device 20 of the present disclosure can be configured suchthat outer length, width and depth dimensions of the air filter unit 22correspond with the smallest expected air filter compartment dimensionsutilized by several different HVAC system manufacturers. Continuing withthe above example, then, the air filter unit 20 can be configured tohave outer dimensions of 15″×19″×3.5″, and promoted to potential usersas being acceptable for use with any HVAC system requiring a 16″×20″×4″air filter. Upon evaluating the size of the actual air filtercompartment, the user can then, if necessary, effectively expand the15″×19″×3.5″ air filter unit 22 in one or more of the length, width anddepth directions L, W, D as described above, transitioning the airfilter device 20 to an expanded state having dimensions correspondingwith those of the actual air filter compartment. Similar benefits can berecognized in other, non-HVAC air filter applications, such as with roomair purifier filters, window air filters, etc.

The air filter devices and related methods of use of the presentdisclosure provide a marked improvement over previous designs. Bypromoting simple, manual expansion in one or more of the length, widthand depth directions, the air filter devices of the present disclosureafford a user the ability to achieve a “best fit” with the air handlingdevice to which the air filter is installed.

Although the present disclosure has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges can be made in form and detail without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. An air filter device comprising: an air filterunit including: a filter media assembly defining a perimeter, an outerframe assembly arranged about the perimeter and establishing exteriorlength, width and depth dimensions of the air filter device in aninitial state; and an expansion unit configured to effect an expandedstate of the air filter device; wherein at least one of the exteriorlength, width and depth dimensions of the air filter device is greaterin the expanded state than in the initial state.
 2. The air filterdevice of claim 1, wherein the at least a portion of the expansion unitis configured for selective assembly to the outer frame assembly.
 3. Theair filter device of claim 1, further comprising packaging containingthe air filter unit and the expansion unit in the delivery condition. 4.The air filter device of claim 1, wherein an entirety of the expansionunit is provided apart from the air filter unit in the deliverycondition.
 5. The air filter device of claim 1, wherein the expansionunit includes at least a first standoff configured for selectivemounting to the outer frame assembly, and wherein the first standoffincludes a standoff body and an adhesive disposed on a face of thestandoff body.
 6. The air filter device of claim 5, wherein the firststandoff is sized for mounting to an end frame member of the outer frameassembly in the expanded state, and further wherein upon mounting of thefirst standoff to the air filter unit, the length dimension of theexpanded state is greater than the length dimension of the initial stateor the width dimension of the expanded state is greater than the widthdimension of the initial state.
 7. The air filter device of claim 1,wherein the outer frame assembly includes a first frame member coveringa first edge of the perimeter, and further wherein the expansion unitincludes a first flange configured to project from the first framemember in the expanded state.
 8. The air filter device of claim 7,wherein the first side flange defines a fixed end attached to the firstframe member and a free end opposite the fixed end, and further whereinthe expanded state includes the free end laterally spaced from the firstframe member.
 9. The air filter device of claim 7, wherein outer frameassembly further includes a second frame member covering a second end ofthe perimeter, and further wherein the expansion unit further includes asecond flange configured to project from the second frame member in theexpanded state.
 10. The air filter device of claim 9, wherein theexpansion unit further includes a deflection device configured to biasthe free end away from the first frame member.
 11. The air filter deviceof claim 10, wherein the deflection device includes a deflection bodyconfigured for placement between the first frame member and the firstflange.
 12. The air filter device of claim 11, wherein the deflectiondevice further includes an adhesive disposed on a face of the deflectionbody for selectively securing the deflection body to the first framemember.
 13. The air filter device of claim 8, wherein the first flangedefines a fold line between the fixed and free ends, wherein the firstflange includes a first portion between the fixed end and the fold line,and a second portion between the fold line and the free end, and furtherwherein the expanded state includes second portion overlapping the firstportion.
 14. The air filter device of claim 7, wherein the first flangeincludes a panel and a first tab, wherein the panel defines a fixed endpivotably connected to the first frame member, a free end opposite thefixed end, and opposing, first and second sides, further wherein thefirst tab projects from the first side.
 15. The air filter device ofclaim 14, wherein the first tab terminates at a leading end opposite thefirst side, the leading end configured to selectively interface withrespective ones of a plurality of slots.
 16. The air filter device ofclaim 15, wherein the outer frame assembly includes a second framemember covering a second edge of the perimeter, the second frame memberarranged orthogonal to the first frame member, and further wherein theplurality of slots are defined in the second frame member.
 17. The airfilter device of claim 16, wherein the first tab and the plurality ofslots are configured to selective lock the panel at a plurality ofdifferent angular orientations of the panel relative to the first framemember.
 18. The air filter device of claim 1, wherein the perimeterincludes opposing, first and second side edges and opposing, first andsecond end edges, and further wherein the outer frame assembly includesfirst and second side frame members covering the first and second sideedges, respectively, and first and second end frame members covering thefirst and second end edges, respectively, and further wherein theexpansion unit includes a first flange configured to project from thefirst side frame member in the expanded state, a second flangeconfigured to project from the second side frame member in the expandedstate, a third flange configured to project from the first end framemember in the expanded state, and a fourth flange configured to projectfrom the second end frame member in the expanded state, wherein each ofthe flanges includes a fixed end connected to the corresponding framemember and a free end opposite the fixed end.
 19. The air filter deviceof claim 18, wherein adjacent ones of the flanges are slidablyconnected.
 20. The air filter device of claim 1, wherein the filtermedia assembly includes a pleated filter media defining a plurality ofpleats.